Anyone had 'contraction'-like pain with IUD?

Ru
Had my IUD fitted (copper) yesterday - definitely a lot less painful than I thought it would be - but in the evening and all of today I've had contraction-like cramps. At least, that's how I think of them like - I've never been pregnant so I wouldn't know for sure! They're very intense for a short amount of time. Any advice from any lovely ladies using IUDs? X